"The result of two hundred years of solid-state physics. For whatever good that does, it is a continuous pseudo-one dimensional diamond crystal - though it's not actually pure carbon. There are several trace elements in carefully controlled amounts. It can be mass-produced only in the orbiting factories, where there's no gravity to interfere with the growth process."

The first efforts to implement (or at least experiment) with creating materials in orbit occurred in the early 1970's, during the Skylab mission (which was launched in 1973). The station was equipped with a materials processing facility that included a multi-purpose electric furnace, a crystal growth chamber, and an electron beam gun. A bit earlier, in 1969, the Russians experimented with welding in space during the Soyuz missions.